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Longevity Record

Head to head

GLP-1 agonists vs metformin: the metabolic heavyweights, compared

Last reviewed 22 August 2026 · grades regenerate automatically when the evidence changes

One is the most-prescribed diabetes drug in history; the other is the most talked-about drug class of the decade. Both now feature in longevity conversations they were never trialled for. The graded claims below keep the two conversations — metabolic medicine and ageing — properly separate.

GLP-1 receptor agonists

Prescription-only medicine

Randomised trials show substantial weight loss, and the 17,604-person SELECT trial showed fewer cardiovascular events in people with overweight or obesity and existing cardiovascular disease. These are prescription medicines with real side effects, tested in high-risk populations — not longevity drugs, and no trial has examined lifespan as a primary outcome.

Full evidence page →

Metformin

Prescription-only medicine

A proven diabetes medicine; an unproven longevity drug. Randomised evidence for benefits beyond diabetes does not yet exist, and meta-analysis of trials within diabetes found the cardiovascular case weaker than commonly assumed.

Full evidence page →

The honest verdict

On modern trial evidence for hard outcomes, the GLP-1 class is ahead: SELECT showed fewer cardiovascular events in high-risk people with obesity, a bar metformin's cardiovascular meta-analysis has not cleanly cleared. On longevity specifically, both stand at zero: no lifespan-endpoint trial exists for either.

These are prescription decisions, not supplement choices — the comparison that matters is made with a clinician against your own health profile, not a leaderboard. What this page can honestly settle is narrower: the longevity-clinic framing of both drugs currently runs ahead of any ageing evidence.

Sources

Every study behind both columns, each verified against PubMed at build time.

  1. [1]Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes (2023). PMID 37952131
  2. [2]Once-Weekly Semaglutide in Adults with Overweight or Obesity (2021). PMID 33567185
  3. [3]Impact of metformin on cardiovascular disease: a meta-analysis of randomised trials among people with type 2 diabetes (2017). PMID 28770324

Keep reading

Metformin: every claim graded →Every lifespan claim, graded →Grade your own stack →

Educational information, not medical advice. Grades are produced by our published methodology from recorded study facts; prescription decisions belong with a clinician.